<!DOCTYPE html>
<html>
  <head>
    <meta charset="utf-8">
    <title>菜鸟教程(runoob.com)</title>
    <style>
    .flex-container {
    display: -webkit-flex;
    display: flex;
    width: 400px;
    height: 250px;
    background-color: lightgrey;
    }
    .flex-item {
    background-color: cornflowerblue;
    margin: 10px;
    text-align: center;
    }
    .item1 {
    -webkit-flex: 1;
    flex: 1;
    }
    .item2 {
    /*-webkit-flex: 1;
    flex: 1;*/
    flex-basis: 50px;
    }
    .item3 {
    /*-webkit-flex: 1;
    flex: 1;*/
    flex-basis: 70px;
    }
    </style>
  </head>
  <body>
    <div class="flex-container">
      <div class="flex-item item1">flex item 1</div>
      <div class="flex-item item2">flex item 2</div>
      <div class="flex-item item3">flex item 3</div>
    </div>
  </body>
</html>